The present invention relates to a closure system, particularly for door locks, in which the closing of the lock determined by mechanically or magnetically controllable tumblers is variable in that a closure code of the lock corresponds initially to a coding of a first key, and can be varied by reshifting of at least one tumbler element within the lock to the coding of a successor key.
In the known devices of this type which operate on the basis of magnetic release of the closure (European Patent 24 242), the recoding is effected by a tool, for instance in the form of an insertion key, which can be inserted from the outside into the lock through an opening in the lock cover. This key engages into the center of a rotatable carrier. In the rotatable carrier there is located at least one permanent magnet which forms a tumbler element. The carrier can be held detained in different angular positions. Each of the angular positions incorporates a different magnetic coding of the lock. This type of recoding is user-unfriendly and impairs the dependability of operation, including security against breaking-in. In this connection there is the danger, in particular, that an unauthorized person will effect the turning of the carrier by means of a tool and that the lock can no longer be opened by the key which was previously intended for it.
Considerable difficulties can arise if it is not known, in particular upon the existence of several turnable carriers, into what position they have been turned. These possibilities by themselves make it necessary that the possibility of resetting the lock not be made known, insofar as possible, to all users of the lock and that this knowledge and the corresponding tool remain restricted to certain trusted individuals. Accordingly, the recoding of the lock can also not be included in the continuous, normal course of operation as is, for instance, frequently the case in hotel locking systems which operate purely electrically. In those locks which operate with pure magnetic-track coding and on an electronic basis, in order to increase the security of electronic basis and of operation, recoding has been proposed in the manner that a key dispensing device which is present at the hotel reception desk issue a different key in a certain updating program or the like for, in each case, the next-following guest in such a manner that the hotel door lock, after the use of this new guest key, no longer accepts the preceding guest key as a suitable key (cf. Federal Republic of Germany Patent 24 01 602). If, in this connection, wires from the dispensing computer at the reception desk up to each hotel door lock are to be avoided, the hotel door lock must have a corresponding updating program stored in it. This greatly complicates such a lock system. That version, on the other hand, also requires sources of voltage in each individual hotel door lock and includes the disadvantage that disturbances in operation occur when a guest does not enter his room at all with a newly issued key and leaves the hotel without entering the room, in which case the next following guest receives a key which the room door lock cannot accept since the intermediate guest key never became known to it.
In the case of structural forms of locks operating on the basis of mechanical release of the lock and which can be closed with multi-bit keys, a recoding of the closing code of the tumblers is known in the form that upon operation with the first key a barrier must, in addition, be released manually, it eliminating a basic position of the tumblers which is secured by combination engagement, whereupon, upon operating the lock by means of a successor key, the setting of the tumblers to the closing code of the successor key is effected, including the restoring of the combination engagement. These structural forms also have the same disadvantages from the standpoint of operation. If the key is lost, the only thing possible is to destroy the lock.
It is furthermore known from U.S. Pat. No. 3 234 768 to effect a permutation change on cylinder locks. In connection with one of the pin tumblers of this solution, a tumbler member in the form of a ball is provided between core pin and housing pin. At the height at the place of separation between the pin bore and the turning gap of the cylinder core, the closure cylinder housing forms a channel which extends to the outside and the diameter of which is somewhat larger than that of the ball. If this cylinder lock is actuated with a first key, then this key in addition to arranging the other pin tumblers, arranges the special pin tumbler in such a manner that the place of separation between ball and housing pin lies at the height of the core turning gap. If this first key is to be blocked out, this can be done with a successor key, the so-called occupants key. By means of the latter, upon the key insertion movement, in addition to the other pin tumblers, the special tumbler is controlled in such a manner that the place of separation between core pin and ball is located at the height of the core turning gap. Upon the following closure turning, the ball passes outward through the channel. The special pin tumbler then operates in the same way as the others. A closing action can no longer be effected by means of the first key. Furthermore no further permutation change can be obtained unless the ball is introduced again in some way.